In order to obtain the precipitation distribution of high resolution in the upper-middle reaches of Yangtze River,this paper analyses the annual precipitation on the basis of the precipitation data of 613 meteorological stations from 1992 to 2001 with an interpolation method which adapts to the Geographic Information System(GIS).The result shows that the effect of the SIA based on the DEM of 4km resolution is preferable.This method improves the computational accuracy,embodies the precipitation changes with topographty and the distributive incontinuity of precipitation,and solves the problem of the precision of the spatial interpolation of precipitation under complicated topographty condition.